Again, the mode calculators are based on the entire surface area being fully reflective, down to the lowest LF. Concrete bunker.
There are other issues. Most calculators treat all modes equally, which is nonsensical.
Furthermore many of the classic ratios are suited to Concert Halls and do not scale at all.
I may seem a bit emphatic here, but Stuart is also cautioning you. One experience in particular, I optimised a green field studio room to the nth degree using this fascinating tool.
http://forum.studiotips.com/viewtopic.php?t=2235
I got every square centimetre up to the planning limit. My dimension passed all 4 different criteria.
The resulting build had a dominant 50Hz boom. Ouch!
I am curious as to the angled cloud? I guess a slight benefit in angles of incidence, a slightly varied depth. Visually nice to get away from the right angles too.
Given that is is nearly full width, I would suggest going full width. There is a lot of LF absorption to be had at those wall ceiling corners.
Given that you are going the full fibre route, I would too, I recommend a skim through boggy's pictures of builds in progress. You might get some framing tips.
DD